SUMMARY The isolated dog kidney was perfused with blood containing 1 m-u. arginine vasopressin/ml. In other experiments 40 or 50 m-u./min. were infused into three intact dogs. Antidiuretic activity was measured in renal venous blood, arterial blood, and in the urine. Renal blood flow was determined directly in the perfused dog kidney and by p-aminohippuric acid clearance in the intact dog; glomerular filtration rate was measured by either inulin or creatinine clearance. About 38% of the hormone was extracted from the arterial blood in its passage through the kidney. Of the total amount of hormone infused, about 18% was eliminated by each kidney. The quantity of vasopressin extracted from the blood was greater than that excreted in the urine, indicating that the hormone is inactivated by the kidney. In intact dogs, the amount of hormone filtered by the kidney was less than that excreted, suggesting tubular secretion. It was calculated that the release of endogenous arginine vasopressin induced by the stimuli of anaesthesia and surgery was between 3 and 7 m-u./min. and that approximately 15% of the endogenous hormone was excreted. Ultrafiltration of dog plasma at three different concentrations of arginine vasopressin (30, 100 and 290 μ-u./ml.) showed that binding was reduced as the concentration was raised and that at the concentration of hormone in the experiments, less than 30% was bound. The difficulties of relating these findings at artificially high blood concentrations to those at physiological blood concentrations of vasopressin are discussed.
Behavioral data were collected during the breeding season on eight pairs of Hawaiian crows (Corvus hawaiiensis) housed at two facilities on different islands. All data were collected from videocamera time-lapse recordings of the nesting platforms. Behaviors included frequency of nest cup manipulation, percent of time spent on nest, allopreening, play, and stereotypy. The number of breeding pairs increased from four in 1996 to six in 1997, to seven in 1998, and to eight in 1999. Five of the older birds (three males and two females) were solitaryreared for most if not all of their first year, while the remaining 12 birds were all socially reared. Significant differences were found between isolate-and sociallyreared birds, with isolate-reared birds having higher rates of solo play (P = 0.0041) and stereotypies (P = 0.0090). Pairs that were comprised of at least one isolatereared bird engaged in significantly less allopreening (P = <0.0001) than pairs in which both birds were socially reared. From 1996 to 1999, 87 eggs were laid, with a mean of 1.88 ± 0.24 SEM eggs per clutch. Only three females produced clutches every year, and they were responsible for 85.1% of the eggs laid. Although not significant, the mean number of clutches produced per pair decreased from 2.50 ± 0.65 in 1996 to 0.87 ± 0.99 in 1999. Age of females does not appear to be a critical factor in the decrease in clutch production. New pairing combinations are under way in an effort to improve propagation in this highly endangered species. Zoo Biol 21: 59-75, 2002.
Puppet-reared and parent-reared captive-bred California condor (Gymnogyps californianus) juveniles were studied before their release into the wild. Behavioral data were collected during social interactions within two cohorts of juveniles (N = 11) and their adult mentors (N = 5). The purposes of this study were to (1) document the social behaviors of mentored juvenile California condors, and (2) compare social behaviors for two different rearing methods (puppet-reared versus parent-reared) during two phases of the mentoring process (San Diego Wild Animal Park versus release sites). Of the 17 behaviors examined by 2 x 2 analyses of variance (ANOVAs), two significant interactions between the rearing method and mentoring phase were found: pulls feathers and feeds alone. For both behaviors, parent-reared condors engaged in these activities more often at the zoo and less often at the release pens than did the puppet-reared condors. The main effect of rearing was also significant for two behaviors: near others, and receives contact aggression from other. Parent-reared birds were more likely to be near another bird and receive contact aggression, regardless of mentoring phase, than puppet-reared birds. The effect size for 16 of the 17 behaviors was greater for the rearing method than for mentoring phase. Rearing method differences may persist long-term, as parent-reared adult mentors were significantly more aggressive than puppet-reared adult mentors. Dominance relations were examined for both cohorts, with the first cohort exhibiting a strong linear relationship (h' = 0.86, P = 0.018), whereas the second cohort exhibited a moderate but non-significant linear hierarchy (h' = 0.63, P = 0.21). The rearing method had no effect on dominance among the juveniles, but adults were probably dominant to juveniles (P = 0.052; the difference was nearly significant). Although social behaviors between the two rearing groups were similar in most respects, this study is the first to document measurable differences between puppet- and parent-reared captive-bred California condor juveniles. Zoo Biol 27:1-18, 2008. (c) 2007 Wiley-Liss, Inc.
In order to test the effectiveness of captive‐rearing and release strategies for future restoration of birds in Hawai'i, this pilot study was conducted in forests where introduced avian disease and mammalian predators were present. Methodology used resulted in the first successful hatching of Drepanidinae eggs in an incubator and subsequent hand‐rearing of chicks from hatch. Sixteen Common 'Amakihi (Hemignathus virens virens) (mean hatch weight = 1.4 g) were hand‐reared. Two different reintroduction strategies were evaluated for small honeycreepers. Known mortality in the wild after release was due to mosquito‐transmitted disease (avian malaria and pox). This pilot study shows that the techniques necessary to hatch, rear, and release endangered Hawaiian honeycreepers are available. However, restoration efforts will probably not succeed unless mosquito‐free, predator‐controlled reintroduction sites are available or strategies are developed to decrease mortality in naive honeycreepers exposed to disease after release. © 1996 Wiley‐Liss, Inc.
The Peregrine Fund, Boise, IdahoCalifornia condors are one of the most endangered species native to the mainland United States and are subject of intense effort regarding captive breeding and reintroduction. We analyzed 20 years of California condor egg records from the wild and from three captive propagation facilities for fertility, hatchability, and chick survivability, along with changes in egg size due to multiple clutching. Overall annual mean percent of fertile eggs was 80.2%, hatchability was 87.3%, and chick survivability to Z60 days was 95.5%. One egg-laying site had a significantly lower fertility rate (P r 0.0001) than the other sites, which was probably due to pair incompatibility rather than any physiological factors. Egg volume of the first egg was significantly greater than both the second (t ¼ 6.73, P ¼ 0.0001) and third egg (t ¼ 6.62, P r 0.0001) of the season, while the second egg had a significantly greater volume (t ¼ 3.20, P ¼ 0.0084) than the third egg. Chicks from the second egg (t ¼ 3.24, P ¼ 0.029) and third egg (t ¼ 7.94, P ¼ 0.0014) of the season were significantly smaller than chicks from the first egg of the season. The decrease in egg measures and chick hatch weight due to multiple clutching did not affect hatchability or chick survivability. There were significant positive relationships (Po0.0001) between fresh egg weight and chick hatch weight and between egg volume and chick hatch weight, as well as between fresh egg weight and egg volume. In spite of the decrease in fresh egg weight, egg volume and chick hatch weights, due to egg removal to stimulate double and sometimes triple clutching, the captive propagation program has been
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